Starting device for internal combustion motors



Feb.15,1944. R UUNGSTROM 2,341,633

STARTING DEVICE FOR INTERNAL COMBUSTION MOTORS Filed Feb. 25; 1940 4 Sheets-Sheet 1 Z a VEN TQR BY W! v I k 5,7 Z ATTORNEY e 1944- F. LJUNGSTRGM 2,341,533

STARTING DEVICE FOR INTERNAL CQMBUSTION MOTORS Filed Feb. 25, 1940 4 Sheets-Sheet 2 vex r02 1 194 F. LJUNGsTROM 2,341,6 3

STARTING DEVICE FOR INTERNAL COMBUSTION MOTORS Filed Feb. 23, 1940 4 Sheets-Sheet 3 Feb. 15, 1944. LJUNGSTROM 2,341,633

STARTING DEVICE FOR INTERNAL COMBUSTION MOTORS Filed Feb. 23, 1940 4 Sheets-Sheet 4 Afro/Mair Patented Feb. 15, 1944 2,341,633 ICE STARTING DEVICE FOR INTERNAL COMBUSTION MOTORS Fredrik Ljungstriim,

Aktiebolaget Sweden,

Lidingo, Sweden, ass'ig'nor to Bolinder-Munktell, Eskilstuna, a corporation of Sweden Application February 23, 1940, Serial No. 320,298 In Sweden February 13, 1939 10 Claims. ('01. 185-40) The invention relates to a spring starting device for internal combustion motors provided with springs which are in strained condition adapted to deliver a turning moment to the crank shaft of the motor. The invention is primarily intended for motors operating with crude oil, for

instance for two-stroke cycle Diesel-engines. The invention has for its main object to provide a starting device of this kind which is utterly reliable in operation and simple to handle. A turning moment is by the springs applied to the crank shaft of a Diesel-motor, for example, being great enough to overcome the frictional resistance within the motor evenat low temperatures, and simultaneously also great enough to supply the workrequired to obtain a quick and powerful compression stroke with a rapid rise of the temperature during the compression stroke in conse quence thereto, without too much of the heat formed through the" compression being transmitted through convection to the cylinder walls' or the surface of the piston; The energy supplied by the springs may during half a revolution. of' the motor exceed and be the double of or still greater than the intrinsic power development of. the combustion motor during one working stroke, without this causing any difiiculty or too large dimensions. in the apparatus. The motor, the

piston of which. at. the moment of startingv takes.

a position at the beginning of the compression stroke, compressesduring this first compressionstroke the stationary fresh air enclosed withinthe cylinder at a considerablespeed. By reasonof this the compression is rendered adiabatic as far as possible, partly by thelfact that it takes place without disturbing-eddies apt'to increase the heat transmission to thewalls of the compression chamber, and partly by thefact that this first compression takes place rapidly, wherebythe time for heat transmissionis reduced to-a minimum. As a consequence, a powerful and safe ignition of the fuel is produced;.ensuring a safe, quick and immediate start;

In addition to the advantage of the rapid and safe start, the motor unit according to the invention may in its entirety be made appreciably lighter, inasmuch as any-wheel of considerablysmaller weight maybe used. In a two-stroke cycle motor, for example, the fly-wheel may thus be advantageously arranged within the crankcasing and simply be concentrated to the cranks,

whereby the detrimental space is also reduced in the crank casing, while the total shaft length' of the motor becomes smaller.

Other andmore detailedobjects of the invention together with the-advantages to be derived from its use will be more fully explained in the following'description ofthe several forms ofap paratus for carrying the invention into eifect,

Fig. 4 through" a spring" starting device in ar cordance' with the invention; I v

Fig. 4 is a section on the line IV'IV of Fig. 3. In Figs. 3 and 4', as well as in the subsequent Figures, certain partsare removed for sake of clearness;

Fig; 5 is a plan View of thei'sam'e'embodiment; v

Fig. 6' shows a section on the lines VI=- 'VI of' Figs; 4 and 7, illi is'trat'ing' the springs together with acrank mechanism the same; g

Fig. '7 is a section on theline VII-VII of Fig. 6; Fig. 8 is a plan View of a detailof Fig. 6;' Fig; 9 is a section on'the linesIXIX of Figs. 4', .7 and 10; I Fig. 10 is a section on theline-X+X of Fig. 9. In the embodiment accordin'gto Figs. 1' and 2,

a detail pertaining to reference numeral 50 denotes a shaft which isrotatably mounted in bearings 31' and isfo'rmed with cranks 5| connected to two powerfulhelical;

springs 52, for instance by rods 53; 5 4. The springs 52' are" opposed but being" connected to cranks set apart; augment each other. When the shaft 50 isrotated' by the motoror by hand, they'are'strained and'released at the same Theshaft 50 carries twofrictiondisks 55 tions 56a, 56b. A'bell crank lever 57 ispivotal1y' portion" 56a as'at 58. One end of the lever" 5'! is'pivotally connected to alinkor mounted on the the like 65, as' at 59, which is mounted at its other-end on theportion 56b asat 10. Each lever 51 is pivotally connected at its otherend toj a'sort' of connecting rod i2, as at H, which is in turn pivotally mounted on a crank 13" on asha'ft 1 4; which is rotatably supportedin fixed bearings7 5. When 'the'shaft 14 "is turned in the direction indicated by thearrow l6, the'crank'lii'being inthe position shown, the right hand rod 12 is'place d under tension and'pivots'th'e right handleve'r 51' in a. counter-clockwise direction, as viewedin Fig. 2," about the point gettier so as to tightly disk .55. Thereafter, continued rotatin of right- 56a and 56b "of the clutch intended for straining These-frictionclutches are" open in one place- 58' to thereby cause" the link 6Uto draw the clutch parts 56d andEBb to clamp'thein around the and transmitrotation to disk 55 in the direction of arrow 11. In the meantime the left-hand rod 12 is placed under compression by the rotation of crank 13 and pivots the left-hand lever 51 in a clockwise direction about point 58, thus spreading the parts 56a and 56b of the left-hand clutch. This clutch is thereby maintained in disengagement from disk 55, and continued rotation of crank 13 causes the left-hand clutch 56 to rotate freely with respect to the disk 55 in the opposite direction thereto. The right-hand clutch 56 remains engaged to the disk 55, as above described, during a one half revolution of shaft 14. Thereafter, this clutch becomes disengaged, and inasmuch as the cranks 13 are set 189 apart, the left-hand clutch becomes engaged and continues the rotation of the shaft 59 in the direction of arrow 11. The disks 55 and the shaft 59, respectively, move comparatively slowly during the straining of the springs, so that any lubricating oil present between the friction surfaces of the members 55, 56 will have sufficient time for being pressed off these surfaces each time the members are to effect another frictional engagement.

Rigidly secured to the shaft 14 is a ratchet disk 83 and an operating lever 84 which may be movably arranged between guide rails 85 in known manner. The lever 84 is provided with a pawl 86 engaging the ratchet teeth of the disk 83. Extending from the lower portion of the lever 84 in Fig. 1 is an arm 81 which is pivotally connected to an arm 88. The arm 88 is connected with a spring 89 tending to move the same against a disk 99 on'the shaft 59, said disk being provided with a notch 9 I.

By reciprocating the operating lever 84 the shaft 14 will be moved round step by step. The lever devices extending from the two cranks 13 are caused alternately to strain and to release the respective friction members 56 for every. half a revolution, and the shaft 59 is thus turned while the springs 52 are being strained. This straining of the springs takes place during a turning movement of the shaft 59 of half a revolution. When the springs 52 have been brought into their strained position they are on dead center, and the arm 88 will snap into the notch 9| under the infiuence of the spring 89. A further reciprocation of the lever '84, and hence of the lever 81 which is fixed thereto, causes the arm 88, the lower end of which is in engagement with notch 9|, to rotate the shaft 59 sufficiently to turn the cranks off dead center, whereupon the stressed springs 52 apply a large torque to the shaft. While turning of the shaft 59 by means of the lever 81 and arm 88, does not result in the high torque multiplication which is obtained by the mechanism including the clutches 56, it nevertheless is sufficient to turn the cranks 5| off dead center, inasmuch as this does not require any additional stressing of the springs 52, but the force need be only sufiicient to overcome friction.

The shaft 59 has a disk 92 rigidly secured thereon. Arranged about the disk 92 is a circular gripping member 93 which is in turn inserted intoa drum 94 rigidly connected to the fly-wheel 2| and the crank shaft of the motor. When the spring-starter is not functioning, there is an annular clearance between the members 93 and 94. The elements 92, 93 are interconnected by a double-armed lever 95 and two links 96, 91. The gripping disk 93 is open in one place, and the links 96, 91 are pivotally connected each withan open end of the gripping disk. The link 96 is pivoted to the lever 95 at 98, and the link 91 at 99.

The lever between the points 98 and. I99, which latter point designates the bearing point between the lever arm and the disk 92, is preferably longer than the lever between the points 98 and 99. When, upon the realease of the spring force, the shaft 59 is quickly turned in the direction of the arrow I1, the gripping member 93 will immediately open under the influence of the leverand link-device just described, and will be expanded against the drum 94 with a forc of such magnitude that the drum and the motor shaft and fly-wheel connected thereto are clutched to the shaft 59 and hence rotated thereby. At the same time the gripping member serves as a little fly-wheel, the mass of which counteracts a sudden acceleration in the direction of rotation, whereby the member will have an increased tendency toward expanding radially at a beginning acceleration, and will thus instantaneously be firmly pressed against the drum 94 when the springs 52 pass through the dead point position.

The shaft 14 carries a rigid ratchet wheel |9| cooperating with a pawl I92 on an arm I93 which is pivotally connected to the shaft 14. The opposite end of the arm I93 is formed with a contact shoe I94. the motor shaft, such as the drum 94, is formed with an eccentric surface I95. An arm I96 is pivotally mounted in a rigid support I91, and is pivotally connected with its other end to an arm I98. The arm I98 is provided with an end portion I99 which is preferably bifurcated and adapted to embrace the arm I93. A spring III is adapted to actuate the arm I98, so that the latter tends to move in a direction toward the arm I93. A spring H9 is connected with its ends to the arms I93 and I98 and tends to approach these arms to each other. The shaft 59 carries a disk II2 provided with a notch H3, and the arm I96 is provided with a boss |I4 corresponding thereto.

When the spring members 52 have been brought into their strained position of rest, the lower end of the arm 88 in Fig. 1 is in engagement with the locking notch 9 I. At the same time the tooth N4 of the arm I96 is in engagement with the notch H3 in the disk H2. The latter has resulted in that the arm I98 has been moved by the springs II 9, I II against the arm I93, the fork I99 having raised the arm I93 and its shoe I941 out of contact with the eccentric surface I95.

By turning the operating lever 84 in the direction of the arrow 16, the arm 88 actuates the disk 99 and the shaft 59 so that the springs 52 snap over from their strained position of rest and are brought into function. At the release of the spring force the gripping disk 93 immediately strikes out against the drum 94 and provides a rigid connection between the shaft 59 and the drum, whereby the movable masses of the motor are accelerated and the motor is started. After the spring work has been delivered to the motor upon half a revolution, the pressing force exerted on the drum 94 through the lever device 95, 96, 91 ceases, the drum 94 then continuing to rotate alone together withthe crank shaft of the motor. The release of the spring force resulted in that the end portion of the arm 88 and the boss II4 of the arm I96 were turned outwardly so as to bear on the circular external surface of the disks 99 and H2, respectively. The arm I98 has thus been moved away from the Upon continued rotation of the motor an oscil- A part rigidly connected with latcry reciprocating. movement is imparted to the arm I03 by reason of the eccentric surface I05, the pawl I02 then turning the disk NH and the shaft 10 in a stepwise fashion in the direction of the arrow 76. The shaft 50 is thus rotated by the motor so as to stress the springs 52. When the strained position of rest of thesprings has again been reached, the pawl 88 and the boss H4 will again enter their respective notches. The arm I08 is pulled against the arm I 03 so as to raise the contact shoe I04 so that the rotation of shaft it is automatically interrupted. The springs 52 are hence in fully stressed condition, and are ready to start the motor the next-time.

As will appear from vice may be charged either manually or automatically by the motor itself. By the fact that the starting mechanism has a very small mass relatively to the movable parts of the motor, the same may be released or connected to and disconnected from the motor'without disadvantage even at the full number of revolutions. Therefore, if the starting device would happen to be released by mistake while the motor is in operation, this will cause no damage whatever to the apparatus. 3 It may thus be attended to by technically quite unskilled people.

In the embodiment according to Figs. 3-10, which shows a constructive realization of the inventive idea disclosed same reference numerals have been used as in these figures for corresponding parts. The starting device is arranged in a rigid outer casing I20, in which the shafts 50 and 74 are mounted. As described hereinabove, the shaft 50 is formed with cranks ti cooperating with connecting rods 53, 5G, for instance in the form of U-bent round irons or the like. The connecting rods 53, 54 are pivotally mounted as at i2I (Fig. 6) in an upper and a lower yoke E22 and 123, respectively. These yokes extend between parallel guides I 2 (see particularly Fig. 8). The guides I24 are rigidly connected with the side walls of the external casing by means of screws or the like. The guides I24 are each surrounded. by a helical spring 52, the end portions of these springs bearing against the yokes I22, E23. At the straining of the starting device the end portions of the springs are pressed toward one another, so that the yokes I22, 523 receive the same straining pressure.

The shaft 50 is formed with two cylindrical friction surfaces 55 (Fig. 4), preferably one on each side of the cranks 5I, which surfaces are embraced by friction clutch members 56 of the same general construction as that described above in connection with Figs. 1 and 2. Thus the element 55a (Fig. 9) of the friction clutch is pivotall connected to the arm 57 as at 58, said arm being pivotally connected to the arm 72 as at H, which latter arm is mounted on the respective cranks 73 (Fig. 4). The lever 51 is mounted as at 50 in the one end of the link 60,

the other end of which is mounted in the clutch member 561) as at 70. Fig. 9, the pivot pin 59 is adapted to move freely relatively to the member 56a. When the shaft "I4 is turned in the direction of the arrow it, the two clutch members 56 are alternately brought into function so as to carry along the shaft 50 in the direction of rotation 'I-I.

A handle 06 (see particularly Fig. 3.) extends outside the casing I20. The handle 34 is con-- nected over a coupling I25 to the shaft M in such manner that this shaft maybe turned in the direction of the arrow I5 (Fig. 9) while bethe above, the starting dein Figs. 1 and 2, the

As will be seen from.

shaft is then caused to ing locked in the opposite direction. Pivotally secured to a coupling sleeve 126 carrying the handle is an arm 88 actuated by the spring v89, the other end of which arm is adapted .to'cooperate with a cylindrical portion of the shaft, which has a notch 9|, as described above. The same cylindrical portion of the shaft 50 is provided with a notch II3 intended to cooperate with a boss II 4 on the arm I06 mounted with its one end in the, casing as at I01.

The drum 94 rigidly connected with the motor shaft surrounds the circular gripping member 93 which is movably connected to the shaft 50 over the links 95, 96, 91. When the starting device is not in function, there is a clearance between the member 03 and the drum 94. Provided in the drum 94 is the eccentric surface I05. Over a second coupling 125 the shaft 14 carries the arm I03 provided with the contact shoe I00. Through the rod I08 the arm I03 is in movable cooperation with the arm I06, which, when the boss IM thereof is adjacent the recess H3 brings the contact shoe I0 3 out of engagement with the eccentric surface I05 under the influence of the spring HI. The spring I I0 is preferably arranged within a sleeve I30, which is pivotally mounted at its upper end on the arm I03, as shown in Fig. 3.

The mode of operation of the apparatus according to Figs. 3-10 is altogether the same as that described hereinabove.

The invention may obviously be varied in many respects Without departing from the idea of the same. It is applicable in all types of internal combustion motors. The primar shaft the same time replaced by a shaft provided with a pinion meshing with said gear wheel. When the secondary rotate by means of the members 83 and I M or I25 the shaft 50 obviously obtains a slower rotary movement corresponding to the ratio of gear. On discharging the spring to start the clutches operate on the secondary shaft 14 alone in the same manner as the clutch 55, 56 operate on the shaft 50, as described above.

What I claim is: I

1. A starting device for internal combustion motors including a starter shaft, spring means having one end connected to a stationary abutment and the other end connected to said shaft eccentrically with respect to the axis of rotation of said shaft so as to be stressed by a one-half revolution of said shaft and to be relieved of stress by the following one-half revolution of the shaft in the same direction, and means for connecting said starter shaft to the crank shaft of the motor at a one to one speed ratio.

2. A starting device for internal combustion motors including a starter shaft, spring means connected to said shaft eccentrically with respect to the axis of rotation of said shaft so as to be stressed by a one-half revolution of said shaft and to drive the shaft during the subsequent one-half revolution in the same direction, and means including a clutch for connecting said shaft to the motor shaft at one to one speed ratio, said clutch being automatically engageable by a sudden acceleration of said starter shaft and automatically disengageable by rotation of the motor shaft at a speed higher than that of said starter shaft, and remaining disengagedduring relatively slow rotation of said starter shaft.

3. A- starting device for internal combustion motors including a starter shaft, spring means connected to said shaft eccentrically with respect to the axis of rotation of said shaft so as to be stressed by a one-half revolution of said shaft and to drive the shaft during the subsequent one-half revolution in the same directtion, a drum secured to the shaft of the motor, a friction member associated with said drum, an arm eccentrically connected to said starter shaft and linked to said friction member so that relative rotation between said starter shaft and said member caused by sudden acceleration of the starter shaft and the inertia of the friction member causes said arm to frictionally engage said member With said drum.

4. A starting device for internal combustion motors including a starter shaft, spring means connected to said shaft eccentrically with respect to the axis of rotation of said shaft so as to be stressedby a one-half revolution of said shaft and to drive the shaft during the subsequent one-half revolution in the same direction, a drum secured to the shaft of the motor, a split band associated with said drum, an arm having one end eccentrically connected to said starter shaft, a first link connecting the other end of said arm to one end of said band, and a second link connecting an intermediate point of said arm to the opposite end of said band.

5. A starting device for internal combustion motors including a starter shaft, spring means connected to said shaft eccentrically with respect to the aXis of rotation of said shaft so as to be stressed by a one-half revolution of said shaft and to drive the shaft during the subsequent one-half revolution in the same direction, clutch means for connecting said shaft to the motor shaft automatically engageable by a sudden acceleration of said tarter shaft and automatically disengageable by rotation of the motor shaft at a speed higher than that of said starter shaft, and means for rotating said starter shaft to stress said spring at a speed so slow that said clutch means remains disengaged even if the motor shaft is stationary.

6. A starting device for internal combustion motors including a starter shaft, spring means connected to said shaft eccentrically .with respect to the axis of rotation of said shaft so as to be stressed by a one-half revolution of said shaft and to drive the shaft during the subsequent one-half revolution in the same direction, clutch means for connecting said shaft to the motor shaft automatically engageable by a sudden acceleration of said starter shaft and automatically disengageable by rotation of the motor shaft at a speed higher than that of said starter shaft, a third shaft, means for rotating said third shaft step by step, one way clutch means for transmitting said rotary motion to said starter shaft to stress said spring, the speed of rotation of said starter shaft being so slow that the first mentioned clutch remains disengaged even if the motor shaft is stationary.

'7.A starting device for internal combustion motors including a starter shaft, spring means connected to said shaft eccentrically with respect to the axis of rotation of said shaft so as to be stressed by a one-half revolution of said shaft and to drive the shaft during the subsequent one-half revolution in the same direction, clutch'means for connecting said shaft to the motor shaft automatically engageable byasudden acceleration of said starter shaft and autoto said third shaft the first mentioned clutch remains shaft matically disengageable by rotation of the motor shaft at a speed higher than that of said starter shaft, a third shaft, a lever ratcheted for slowly rotating it manually step by step, and one way clutch means for transmitting said rotary motion to said starter shaft to stress said spring, the speed of rotation of said starter shaft being so slow that disengaged even if the motor shaft is stationary. i

8. A starting device for internal combustion motors including a starter shaft, spring means connected to said shaft eccentrically with respect to the axis of rotation of said shaft so as to be stressed by a one-half revolution of said shaft and to drive the shaft during the subsequent one-half revolution in the same direction, clutch means for connecting said shaft to the motor shaft automatically engageable by a suddent acceleration of said starter shaft and automatically disengageable by rotation of the motor shaft at a speed higher than that of said starter shaft, a third shaft, a lever ratcheted to said third shaft for rotating it step by step, a cam rotatable by said motor shaft and operative to rock said lever, and one way clutch means for transmitting said rotary motion to said starter shaft to stress said spring.

9. A starting device for internal combustion motors including a starter shaft, spring means connected to said shaft eccentrically with respect to the axis of rotation of said shaft so as to be stressed by a one-half revolution of said and to drive the shaft during the subsequent one-half revolution in the same direction, clutch means connecting said shaft to the motor shaft automatically engageable by a suddent acceleration of said starter shaft and automatically disengageable by rotattion of the motor shaft at a speed higher than that of said starter shaft, a third shaft, a lever ratcheted to said third shaft for rotating itstep by step, a cam rotatable by said motor shaft and operative to rock said lever, one way clutch means for transmitting said rotary motion to said starter shaft to stress said spring, and means for automatically disengaging said lever from said cam just before said starter shaft is rotated to a dead center position with respect to the eccentric connection with said spring.

10. A starting device for internal combustion motors including a starter shaft, spring means connected to said shaft eccentrically with ,respect to the axis of rotation of said shaft so as to be stressed by a one-half revolution of said shaft and to drive the shaft during the subsequent one-half revolution in the same direction, clutch means for connecting said shaft to the motor shaft automatically engageable by a sudden acceleration of said starter shaft and automatically disengageable by rotation of the motor shaft at a speed higher than that of said starter shaft, a third shaft, a lever ratcheted to said third shaft for rotating it step by step, a cam rotatable by saidr'notor shaft and operative to rock said lever, one way clutch means for transmitting said rotary motion to said starter shaft to stress said spring, means for automatically disengaging said lever from said cam just before said starter shaft is rotated to a dead center position with respect to the eccentric connection with said spring, and a manually operable lever ratcheted to said third shaft for rotatingsaid starter shaft past dead center.

FREDRIK LJUNGSTRfiML 

